1. Field of Invention
The present invention relates to a method for testing the connection between a USB port and a USB host controller through a simple circuit and the device for the same.
2. Related Art
The universal serial bus (USB) is a new generation peripheral interface, which is set forth by seven software and hardware companies, including Intel, Compaq, NEC, DEC (Digital), IBM, Northern Telecom, and Microsoft. The transmission speed of this interface can be either 1.5 Mbps or 12 Mbps. It can connect at most 127 peripheral devices. Since its transmission speed is much faster than a parallel port or a serial port used in a personal computer (PC), therefore the USB significantly increases the transmission efficiency between the computer and its peripheral devices.
The Windows 98 operating system supports the USB interface. It sets a unified specification for the peripheral communications port of a PC and supports almost all peripheral devices, such as the USB interface network card, keyboard, mouse, joystick, optical disk drive, tape drive, printer, scanner, digital camera, etc. These USB devices do not only support the plug-and-play function but also the hot-plug function.
Through the USB, peripheral devices of different types (such as the mouse, keyboard, joystick, speaker, modem, scanner, optical disk drive, etc) can be connected to a PC through the same interface, simplifying the PC interface type. Moreover, the USB has such advantages of a lower cost, more connections, occupying less system resources and supporting a plurality of transmission protocols (at most four different protocols).
The current test method is to plug a USB device (such as a USB mouse) to the USB port on a PC to check the connection of the USB port by testing the USB device. However, there are the following problems:
1. The test cost increases because it needs a USB device.
2. When the USB device does not function normally, it is impossible to determine whether it is because improper connection of the port or the USB device does not function correctly. This may leads to incorrect test conclusion.
3. When the condition in 2 happens, one needs to further check the function of the USB device in order to have a correct test result. This definitely lowers the efficiency of the tests.
It is a primary object of the present invention to provide a simple but effective test method to test the connection of a USB port on a personal computer main board. Using a simple hardware circuit to test the connection can avoid the complication of the current test methods and using a USB device. It can greatly save the cost and prevent incorrect judgments due to improper functioning of the USB device.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.